Usually power is routed from one printed circuit board assembly (PCA) to another printed circuit board assembly using a direct printed circuit board (PCB) to printed circuit board connection using board mount connectors. Although board mount connectors provide easy assembly, they typically require significant board space. Not all geometry constraints allow for a direct board to board connection. In some cases, the power requirements and geometric constraints of the PCA to PCA connector can be made using a cable/connector or bus bar solution.
Existing solutions which utilize a cable/connector solution for connecting a first PCA to a second PCA include: plastic molded connectors attached to cables which plug into mating connectors on either PCA and uninsulated metal power pins that can be placed on each PCA and then connected by receptacles at the ends of the wire. Electrical connection between the cable mechanism and the PCA is typically made using a mating connector which is soldered to the PCA. A problem with the aforementioned cable/connector solutions is that they have a relatively high electrical impedance. The cable/connector impedance includes the impedance at the interface between the wire and the first connector, the impedance of the interface between the wire and the second connector, and the impedance inherent in the wire itself. A further problem with prior cable/connector solutions is that they can be difficult to assemble for high current applications since high current applications typically require a large wire thickness. The large wire thickness makes the cable/connector solutions difficult to manage in a limited space.
A second solution for electrically connecting a first PCB to a second PCB is a power bus bar. FIG. 1A shows a top view of a conventional bus bar 100 used to electrically connect a first printed circuit board (not shown) to a second printed circuit board (not shown). FIG. 1B shows a side cross-sectional view of a conventional bus bar of the power bus bar shown in FIG. 1A. The bus bar 100 shown in FIGS. 1A and 1B is comprised of a first electrically conductive structure 120 and a second electrically conductive structure 122. The first electrically conductive structure 120 is connected to the power plane of both the first and second printed circuit boards. The second electrically conductive structure 122 is connected to the ground planes of both the first and second printed circuit boards.
Referring to FIG. 1A, the first and second electrically conductive structures 120, 122 are physically located on the same plane and are placed side by side so that the sidewalls of the first and second electrically conductive structures 120, 122 and are separated by a predetermined distance 126. A first insulative layer is placed on the top surfaces of the first and second electrically conductive structures 120, 122. A second insulative layer is placed beneath the first and second electrically conductive structures. The second insulative layer typically has adhesive properties to solidify the positioning of the first and second conductive structures 120, 122 thus preventing movement. Electrical contact between the conductive structures and the PCBs is made by securing each conductive structure to an electrical contact of the PCB. Compared to the cable/connector solution, electrical resistance is decreased. However, because the first and second structures are placed side by side in the same plane, the inductance of the bus bar structure is relatively high. Further, it is desirable to further minimize the geometric requirements of the bus bar connector.
A spatially efficient, reliable high current connector for connecting the ground and power planes of a first printed circuit board to the ground and power planes of a second printed circuit board is needed.